Continuous Glucose Monitoring in Youth With Type 2 Diabetes

The TODAY study and other studies have reported disappointing results of intensive
life-style programs alone or in combination with metformin in maintaining optimal control of
type 2 diabetes (T2D) in adolescents. Continuous glucose monitoring (CGM) has been
successful in lifestyle modification in adults with T2D but use of CGM has not been studied
in youth with T2D. Thus the feasibility of this technology should be evaluated in this
patient population as it may prove to be an effective adjunct to treatment in the future.

Youth with type 2 diabetes will be approached for enrollment in this study. The study will
be explained to volunteers who meet eligibility criteria and informed consent/assent will be
obtained. Demographic data will be recorded. A medical history will be performed. A urine
pregnancy test (in women) will be measured to confirm eligibility. Height, weight, BMI,
percent body fat, fat mass, and fat free mass will be measured. Hemoglobin A1c (HbA1c) will
be measured. After enrollment a blinded CGM will be placed. CGM is a device inserted under
the skin on the abdomen which monitors glucose levels every 5 minutes, recording this
information. CGM is commonly worn by kids with type 1 diabetes. The study will allow
collection of information on glucose variability in much greater detail than can be seen
from intermittent fingerstick glucose values or from an oral glucose tolerance test.
Subjects will meet with a nutritionist to learn how to keep a food record. They will be
given empty food records to complete for each day. They will also be given an accelerometer
and instructed in its use, however they will remain blinded to the data obtained. The study
will be 5 days in length. Subjects will be urged to continue their normal eating and
activity behaviors. During the study period blood sugar and CGM data will be recorded via
glucometer and sensor downloads, dietary intake via food record, and activity via
accelerometer. Glucometer testing of blood glucose is required at least every 12 hours to
calibrate the CGM. To minimize the need for overnight tests to calibrate the CGM, subjects
will be asked to check their blood sugar using a glucometer 3 times a day, preferably
fasting in the morning before breakfast, before dinner, and at bedtime. To optimize the
accuracy of dietary intake records, subjects will be contacted frequently and the food
record information recorded by study personnel. Subjects will be given a "morning checklist"
to keep in a visible area to improve compliance by reminding them to keep study devices with
them all day. At the follow-up visit the CGM will be downloaded revealing blood glucose
tracings for the study period. Additionally the completed food records will be collected and
the accelerometer will be downloaded.

Inclusion Criteria:

- Clinical diagnosis of type 2 diabetes

- Duration of type 2 diabetes ≥ 3 months

- Naïve to continuous glucose monitoring

- Willing to wear a continuous glucose monitor for 5 days

- Willing to check blood sugar at least every 12 hours, preferably 3 times a day

- Willing to wear an accelerometer for 5 days

- Willing to keep a food record for 5 days, including frequent phone contact from the
research staff

- Be in good general health without other acute or chronic illness that in the judgment
of the investigator could interfere with the study or jeopardize subject safety

- Able to give informed consent (for children <18 years, permission from parents and
subject assent will be required)

- Female subjects of reproductive potential must be abstinent or consistently using
appropriate family planning methods

Exclusion Criteria:

- Presence of any medical or psychiatric disorder that may interfere with subject
safety or study conduct

- Use of any medications (besides insulin and/or metformin) known to effect blood
glucose levels, including oral or other systemic glucocorticoid therapy

- Subjects using herbal supplements will be excluded, due to the unknown effects of
these supplements on glucose control

- History of hypoglycemic seizure within last year or frequent hypoglycemia (≥2 time a
month)

- Female subjects who are pregnant, lactating, or unwilling to be tested for pregnancy